Inventive drawings and paintings—accretive, masterful little grids and mazes—make for an upriver safari in an unpredictable mind. Siena is our Paul Klee, taking a line not on a walk but on adrenalin-drenched runs. The pictures range from crackling geometric abstractions and process-dictated designs to varieties of perfervid noodling and spasms of sex-obsessed grotesquerie. Siena’s line is as implacable as an animal’s hunger and as allergic to boredom as a sugared-up child. Let the show wear you out. Leave. Come back for more. Through April 30.